curl --request POST \
  --url https://v2.firstpromoter.com/api/v2/affiliate/contract_documents/{id}/sign \
  --header 'Account-ID: <account-id>' \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "ip": "<string>"
}'

{
  "id": 123,
  "status": "signed",
  "signed_ip": "<string>",
  "contract_version_id": 123,
  "signed_at": "2023-11-07T05:31:56Z",
  "promoter": {
    "id": 123,
    "email": "<string>",
    "name": "<string>",
    "profile": {
      "avatar": "<string>"
    }
  },
  "contract_version": {
    "added_at": "2023-11-07T05:31:56Z",
    "changes_made": "<string>",
    "external_link": "<string>",
    "content_hosted": true
  },
  "contract": {
    "id": 123,
    "name": "<string>"
  }
}